INS and diabetes mellitus: A total of 25,549 patients were identified with diabetes mellitus, mostly identified through antidiabetic or insulin therapy (n = 21,339, 83.5%), ongoing long-term disease coverage for diabetes mellitus (n = 17,371, 68.8%),, or a recorded diagnosis of DM (n = 5,589, 21.8%) during the previous 2 years before the index date (Additional file 3).